Chapter 5. CommunicationsGFK-2222AD April 2018 1915.2.3 Serial Port Pin AssignmentsCOM1 (RS-232, 9-pin Subminiature D Connector)This port has a 9-pin, female, D-sub connector with a standard pin out. This is a DCE (datacommunications equipment) port that allows a simple straight-through cable to connect with a standardAT-style RS-232 port.The CPE310 provides the DCD and RI signals to support point-to-point protocol (PPP).COM1 RS-232 SignalsRX3i CPU, RX3i CRU,and RX7i CPE Models RX3i CPE310 ModelPin No. 78 Signal Name Description Pin No.78 Signal Name Description1 NC No Connection 1 DCD Data Carrier Detect2 TXD Transmit Data 2 TXD Transmit Data3 RXD Receive Data 3 RXD Receive Data4 DSR Data Set Ready 4 DSR Data Set Ready5 0V Signal Ground 5 COM Signal Ground6 DTR Data Terminal Ready 6 DTR Data Terminal Ready7 CTS Clear to Send 7 CTS Clear to Send8 RTS Request to Send 8 RTS Request to Send9 NC No Connection 9 RI Ring IndicatorCOM1 (RS-232, RJ-25 Connector)The CPE302/CPE305 provides RS-232 communications via an RJ-25 connector and requires shieldedcable IC693CBL316.CPE302/CPE305 COM1 RS-232 SignalsPin No. Signal Name Description1 CTS Clear to Send2 TXD Transmit Data3 0V Signal Ground4 0V Signal Ground5 RXD Received Data6 RTS Request to Send78 Pin 1 is at the bottom right of the connector as viewed from the front of the module.
